The present invention relates to substantially odor free, UV curable organopolysiloxane compositions useful as release coatings. More particularly, the present invention relates to the use of a polydiorganosiloxane having condensed epoxyorganosiloxy units and haloarylalkylsiloxy units which can provide for substantially odor free UV curable organopolysiloxane release coating compositions.
In copending application Ser. No. 225,986, there is described silicone release coatings having improved differential release characteristics. A principal feature of the release performance of such coating compositions is the presence of phenolalkyl radicals attached to silicon by carbon-silicon bonds resulting from the platinum catalyzed hydrosilylation of allylphenol onto condensed siliconhydridesiloxy units. Although a controlled release effect can be achieved with such silicone coating compositions, it has been found that residual amounts of unreacted allylphenol are often present in the cured coating resulting in an unpleasant phenolic odor.
In copending application RD-19,356, filed concurrently herewith, improvements in controlled release characteristics of UV curable silicone compositions are achieved without the odor disadvantages of residual allylphenol, by using either C.sub.(8-20) alkyl substituted phenol monomers or readily distillable phenolalkyl substituted disiloxanes as controlled release additives (CRA's).
It would be desirable therefore to provide additional odor-free epoxysilicones, or CRA's for epoxysiloxanes, which would be capable of providing odor-free UV curable epoxysilicone compositions having controlled release characteristics.